Documents required to change your name depend on the reason for your name change. Fortunately, in most cases the documents you'll need should be at hand or easy to get.
Marriage Name Change (Woman)
It's simple for a woman to change her name due to marriage, largely because it is such a common name change. An original marriage certificate or official copy issued by the state, proof of citizenship and a driver's license or similar proof of identity should be presented at the Social Security office, along with their form detailing the change that needs to be made. If you've been married longer than 2 years, make sure that you bring a picture ID (expired is fine) or your birth certificate to show your birth name in order to establish identity.
Once you have received a Social Security card in your married name, you can legally use the changed name. Your marriage certificate, the new Social Security card and a picture ID should be enough for you to update all your other information at the DMV and other important places.
If you're changing your name due to a divorce, replace "marriage certificate" above with "divorce decree"; otherwise, the process is identical.
Marriage Name Change (Man)
It's a little more difficult for a man to change his name due to marriage. Because this is a less-traveled route, you'll need to go to court to complete a legal name change, even if it's to the hyphenated version of your and your wife's names. Fortunately, you may be able to file for the name change yourself or use an inexpensive paralegal to do the paperwork for you, and you may not even have to show up at court in person. Just as in a woman's marriage name change, you will need your picture ID, birth certificate and marriage certificate to prove your identity and valid reason for name change.
Once you've received a court order changing your name, you can use this document and a picture ID in your original name to change your name at the Social Security Administration and other places.
Adoption also requires a court order for name change, but in most cases the name change will be done as part of the routine court proceedings. Because every adoption is different, be sure to ask your attorney what you will need to change or obtain your child's Social Security card in his new name.
Other Reasons for Name Changes
All other reasons for a legal name change will require a court order. The court order and a picture ID in your original or new name should be enough to change your name at all other places.